Administering Platform LSF - SAS

Chapter 33
Running Interactive and Remote Tasks
Load Sharing X Applications
Starting an xterm
xterm on a PC
If you are using the X Window System, you can start an xterm that opens a
shell session on the least loaded host by entering:
% lsrun sh -c xterm &
The & in this command line is important as it frees resources on the host once
xterm is running, by running the X terminal in the background.
In this example, no processes are left running on the local host. The lsrun
command exits as soon as xterm starts, and the xterm on the remote host
connects directly to the X server on the local host.
Each X application makes a separate network connection to the X display on
the user's desktop. The application generally gets the information about the
display from the DISPLAY environment variable.
X-based systems such as eXceed start applications by making a remote shell
connection to the UNIX server, setting the DISPLAY environment variable, and
then invoking the X application. Once the application starts, it makes its own
connection to the display and the initial remote shell is no longer needed.
This approach can be extended to allow load sharing of remote applications.
The client software running on the X display host makes a remote shell
connection to any server host in the LSF cluster. Instead of running the X
application directly, the client invokes a script that uses LSF to select the best
available host and starts the application on that host. Because the application
then makes a direct connection to the display, all of the intermediate
connections can be closed. The client software on the display host must select
a host in the cluster to start the connection. You can choose an arbitrary host
for this; once LSF selects the best host and starts the X application there, the
initial host is no longer involved. There is no ongoing load on the initial host.
Setting up an X terminal to start an X session on the least loaded host
If you are using a PC as a desktop machine and are running an X Window
server on your PC, then you can start an X session on the least loaded host.
The following steps assume you are using Exceed from Hummingbird
Communications. This procedure can be used to load share any X-based
application.
You can customize host selection by changing the resource requirements
specified with -R "...". For example, a user could have several icons in the
xterm program group: one called Best, another called Best_Sun, another
Best_SGI.
Administering Platform LSF 423